Stable dispersions of fatty amine acid salts



United States Patent STABLE DISPERSIONS OF FATTY AIVHNE ACID SALTS Thomas H. Lentz, St. Louis Park, and Joseph W. 0pie and David E. Terry, Minneapolis, Minn., assignors to General Mills, Inc., a corporation of Delaware No Drawing. Application October 5, 1055' Serial No. 538,761

3 Claims. ('Cl. 252-'-311) This invention relates to novel compositions containing fatty amine salts in admixture with other constituents that are easily dispersible in Water. Furthermore, the compositions of this invention upon dispersion form com positions stabilized to a degree heretofore unobtainable.

Fatty amines are long chained aliphatic amines. Theirpreparation from fatty acids by reacting the fatty acids with ammonia to produce the corresponding nitrile and subsequent reduction of the nitrile to amine is a wellknown commercially successful process. Likewise, the use of fatty amines and their salts as' aqueous dispersionsin the ore flotation industry and as corrosion inhibitors is well-known and practiced extensively.-

Although used commercially as shown above the aqueous dispersions of fatty amines and their salts presently employed have disadvantages of varying degree and kind. For instance, the ac'cepted'practice is to prepare 5 to aqueous concentrates prior to their actual use. Previously it was necessary to use hot water (60 to 100 C.) and extended periods of stirring of from 10 to 24 hours in the preparation of these concentrates. Even after this laborious preparation it was not uncommon to have the dispersions break upon standing or dilution with cold water. By break we refer to separation of the dispersion into two phases. For example, when cold water is used to dilute the concentrate, the fatty amine salt frequently separates into stringy, insoluble curds.

It is an object of this invention to set forth various compositions containing fatty amine acid salts which are readily dispersible in water.

Another object of this invention is to disclose various aqueous dispersion of fatty amine acid salts that are relatively stable in water.

It has now been discovered that mixture containing the acid salts of technical grade primary fatty amines and fatty amine distillation residue fulfill the above objects.

Additional advantages and objects of this invention will become apparent to those familiar with the various applications in which aqueous dispersions of fatty amine acid salts are employed.

The fatty amines envisioned by this invention are those derived from fatty acids. These acids are longchained high molecular weight aliphatic carboxylic acids either saturated or unsaturated. The principal source of these fatty acids is from naturally occurring fats and oils in animals and plants. Illustrative of these fats and oils are tallow, greases, soybean oil, corn oil, cottonseed oil, palm oil etc. The bulk of these acids have from 8 to 22 carbon atoms with a preponderance of acids having 18 carbons such as stearic, oleic, linoleic and linolenic acid. Generally speaking the primary fatty amines will have the same number of carbon atoms as the acid or acids usedv as a starting material in their preparation, that e is from 8 to 22 carbon atoms.

In the preparation of the fatty amine from the various fatty acids by the preparation of the nitrile and reduction of the nitrile to amine there are also produced small amounts of secondary and tertiary amines in addition to small amounts of compounds having an unknown structure. The amines resulting from the reduction of the nitrile without subsequent treatment or purification are referred to as technical grade primary amines. These technical grade primary amines contain approximately 85 to 90% primary amine and 10 to of a mixture composed of secondary and tertiary amines, amides, unreacted nitriles, unreacted acids, unsaponifiable matter and minor amounts of unidentified products.

In many instances it is desirable to have a product Which contains a higher percentage of the primary amine.

This may be accomplished by distillation of the technical grade amine described above. Products approaching 100% primary amine may be prepared by distillation of the technical grade amine and the impurities shown above plus pyrolysis products of unknown characteristics are concentrated in the residue, hereafter referred to as fatty amine distillation residue. Analysis of several of these fatty amine distillation residues from technical grade primary amine was carried out so as to determine in so far as possible its characteristics and chemical make-up. Results of these analyses showed that the residues contained from 20 to 30% primary amine, 20 to 30% secondary amine, 5 to 20% tertiary amine, 0 to 10% fatty amide, 0 to 20%, fatty nitrile and by difference 8 to 55% unsaponifiables and pyrolysis products of unknown compositions. The acid number of the residues was from 0 to 1. It should also be noted that until now this fatty amine distillation residue has been comparatively worthless in respect to the distilled or technical grade amines.

The new and novel compositions of this invention are prepared by adding fatty amine distillation residue to technical grade primary amine in a molten condition and subsequently adding the appropriate amount of acid to form the acid salts of the components in the complex mixture. It is possible to employ either organic or inorganic acids in the preparation of the acid salts, hydrochloric acid and acetic acid being two acids that are commonly utilized. Acetic acid is, however, preferred for a variety of reasons. Although fully neutralized amines are preferred, mixtures containing small amounts of free amines may be employed without negating the full benefits of this invention.

Another important element of this invention relates to the proportions of the technical grade primary fatty amine and fatty amine distillation residue which are present in the final mixture. It will be recognized that the exact amount of these components will vary somewhat with the type of starting materials used in the preparation of the amine and in its process of preparation. In any case at least 5% of the mixture should be fatty amine distillation residue. The technical grade primary amine should account for at least 88 to 95% of the total mixture. Thus, the range for the fatty amine distillation residue is from 5 to 12%. The preferred range for the technical grade primary amine being from 90 to 92%, all percentages being figured on a weight basis before conversion to an acid salt.

Other novel compositions encompassed by this invention are the stable water dispersions prepared by mixing 3 the above-described compositions with water at elevated temperatures. These dispersions are stable upon cooling to room temperature and/ or being mixed with additional water. The concentration of these stable dispersions is from 0.05 to by weight of the acid salts of the technical grade primary fatty amine and the fatty amine distillation residue. The novelty of this invention may be illustrated further by reference to the following examples:

Example 1 A control experiment was carried out to measure the time required to disperse technical grade tallow primary amine acetate in water at 65 C. A 3% dispersion was prepared by placing 9 grams of the amine acetate in a beaker and 291 grams of water at 65 C. Was added. This mixture was stirred mechanically at a slow rate, which simulated actual preparation conditions in the field. The time required for complete dispersion was to min-- utes.

Example 2 A mixture of 90% technical grade primary tallow amine and 10% tallow amine distillation residue was prepared by mixing them in molten state. This mixture was then completely neutralized with glacial acetic acid. The method of preparing a 3% dispersion described in Example 1 was repeated with this mixture. The time for complete dispersion was found to be 4 to 6 minutes (or 3 to 4 times faster than Example 1).

Example 3 A ten percent dispersion of technical grade primary tallow amine acetate was prepared with 65 C. water in the same manner as the 3% solution of Example 1. 100 ml. of this 10% solution while. still hot was added to 300 ml. of water at 5 C. resulting in a 2 /2% solution of amine acetate in cold water. The temperature of this dispersion was maintained at 7 to 8 C. for one hour without stirring. At the end of one hour strings or curds of the amine acetate were readily visible in the water.

4 Example 4 The mixture of 90% technical primary tallow amines and 10% tallow amine distillation residue prepared in Example 2 and completely neutralized, Was tested in a manner identical with Example 3. The 10% solution in C. water was complete in 2 minutes. Upon dilution to the 2 /2 concentration and subsequent standing at low temperature, no separation or breaking of the dispersion was observed. The mixture remained completely homogeneous indefinitely.

The reasons for the unexpected stability and ease of dispersion of the compositions of this invention are not fully known. It may be that one portion of the fatty amine distillation residue, such as the secondary amines, tertiary amines, amides, nitriles, acids, unsaponifiables, or the unknown and complex pyrolysis products, is primarily responsible for the beneficial results. Likewise, it may be their combined effect or the effect of two or more of these components. In any event addition of the fatty amine distillation residue, which has heretofore been considered a relative worthless by-product, enhances the value and utility of technical grade primary amine.

Now, therefore, we claim:

1. Acomposition capable of rapid dispersion in water consisting essentially of the acetic acid salts of a mixture composed of 88 to 95% technical grade primary fatty amines and 12 to 5% fatty amine distillation residue,

said: fatty amines having from 8 to 22 carbon atoms.

2. A'compositien capable of rapid dispersion in water consisting essentially of the acetic acid salts of a mixture composed of 90 to 92% technical grade primary fatty amines and 1-0 to 8% fatty amine distillation residue, said fatty ami lfis having from 8 to 22 carbon atoms.

3. A stable water dispersion consisting essentially of from 9.0- to 99.95% water and 0.05 to 10% of the acetic acid, saltsof a mixture composed of 88 to 95% technical grade primary fatty amines and 5 to 12% fatty amine distillation residue, said fatty amines having from 8 to 22 carbon atoms.

No references cited. 

1. A COMPOSITION CAPABLE OF RAPID DISPERSION IN WATER CONSISTING ESSENTIALLY OF THE ACETIC ACID SALTS OF A MIXTURE COMPOSED OF 88 TO 95% TECHNICAL GRADE PRIMARY FATTY AMINES AND 12 TO 5% FATTY AMINE DISTILLATION RESIDUE, SAID FATTY AMINES HAVING FROM 8 TO 22 CARBON ATOMS. 